i'm about to remodel my master bathroom and will be re-doing plumbing. The layout will be the following:
Shower, sink, WC and bathtub.
Here are drawings of what i was thinking of for the rough-in:
*** btw, i know the wye fittings for shower and lavatory are 3x3x3in while they should not. I could not find/draw.
The 3 inches drain cannot be moved and sits below a window. For that reason, there's a 3inches horizontal wet vent that goes left until it meets a thick wall then straight up through the roof. This is the actual drainage setup except we don't have a separate shower and fixtures are moved around a little.
So the plan is:
Shower: horizontal connection to 3 in wet vent through Wye, vented by the 3 in vent.
Sink: horizontal connection to 3 in wet vent through Wye, vented with the use of an AAV. The reason is that there's an exterior wall behind and i live in a cold climate where it can drop to -30 in winter. I think a vent in an exterior wall is not a good idea.
WC: horizontal connection to 3 in wet vent through Wye.
All of the above connected to 3 in drain through a double sanitary tee. The shower is about 7 feet from the 3in stack.
The bathub is on the other side of the 3in stack and would be connected in the 3in sanitary tee with a 1 1/2 to 3in adaptor. It would have a proper vent going 45degrees up until it reaches a wall then up in the attic. The vent would then go horizontal until it meets the 3in vent going through the roof.
I would like to know if this design make sense, what could i do to improve or am i completly wrong?
More specific questions:
1. is the 3in vent going straight up is too far (8 feet) from the stack to act as part of a wet vent?
2. Can i connect the WC the way it is in the drawing?
3. Is the double sanitary tee the proper fitting to allow the wet vented section AND the bathub to drain in the 3in stack? Can i cap the double sanitary tee as there is no pipe going up?
3. is it ok if i use an AAV for the lavatory or i should make some kind of plumbing loop like this:
Father or a 3rd baby (2 weeks old)... the bathroom needs help.